Most of the currently available mobile devices, such as notebook computers, tablet computers and smartphones, have a slim body and a largely increased computing speed. The electronic elements in the mobile devices for executing the computation at high speed also produce a large amount of heat during operation thereof. For the purpose of being conveniently portable, the mobile devices have a largely reduced overall thickness. And, to prevent invasion by foreign matters and moisture, the mobile devices are provided with only an earphone port and some necessary connection ports but not other open holes that allow air convection between the narrow internal space of the mobile devices and the external environment. Therefore, due to the small thickness of the mobile devices, the large amount of heat produced by the electronic elements in the mobile devices, such as the computation executing units and the battery, can not be quickly dissipated into the external environment. Further, due to the closed narrow internal space of the mobile devices, it is difficult for the heat produced by the electronic elements to dissipate through air convection. As a result, heat tends to accumulate or gather in the mobile devices to adversely affect the working efficiency or even cause crash of the mobile devices.
To solve the above problems, some passive type heat dissipation elements, such as heat spreader, vapor chamber, heat sink, etc., are mounted in the hand-held devices to assist in heat dissipation thereof. However, while these passive type heat dissipation elements directly transfer the internally accumulated heat to an outer case, frame or body of the hand-held or the mobile device for dissipation, the rising temperature at the above areas of the hand-held or the mobile device tend to burn a user's hand or face that is in contact with the heated areas, such as the frame or two lateral sides of the hand-held or the mobile device, and therefore causes inconvenience in using the devices.
Therefore, it is important to design and develop a heat insulation structure for hand-held device that provides effective heat dissipation effect to prevent a hand-held device from burning a user's hand due to heat produced by electronic elements in the hand-held device.